Currently, the trolleys used in aircraft to, for example, distribute food to passengers, comprise a main body with a prismatic shape in which the smaller vertical sides allow the access to the interior. The side walls of the trolley, forming the larger sides, have supports for trays and/or drawers in which the food and/or beverage which is individually distributed to each user during the flight is stored. These trays and/or drawers will hereinafter be referred to as storage elements.
Currently, when these storage elements have to be refrigerated for the correct preservation of foods or other items contained therein, the upper part of the trolley (the head) has one or more container trays which are capable of storing carbonic ice, for example. These cold source container trays can have: one or more windows made at their base to facilitate the cold outlet; or no window (which, although it seems absurd, is real). This cold must move downwards, for example, facilitated by the higher density of the gas at lower temperature, through one or two narrow and elongated outlets, made close to the point of passage of the smaller axis of the support panel of these trays. This form of cold transmission, already from the start means that a large part of the cold supplied by the source towards the exterior of the trolley will be lost. One of the cases is that the gap in which these container trays are housed is not hermetic and the actual support base of the container trays hinders the entrance of the refrigerating gas inside the trolley. The entrance is hindered due to having only one or two holes made therein, making another large part of the gas fall on the support panel, which is made in an insulating material (rigid foam), whereby another part of the refrigerating power of the source is lost. Furthermore, but not less important, this gas currently does not reach all the food and beverage storage elements. The cold source container trays are arranged parallel to the lower base of the trolley.
In practice, the cold emanated from the cold source container tray reaches the upper storage trays and/or drawers, the closest ones, located about six centimeters below, such that it is usual for part of their contents to be frozen, making them unsuitable for on-board service. The cold gradually reaches the farthest trays (in a downward direction), weakly reaching the lower ones which are not suitably refrigerated.
This is added to the fact that the inner and outer part of current on-board service trolleys are made of metal, whereby there is another large cold loss since these large panels distribute heat into the trolley, because due to current construction, the heat from the exterior is transmitted by thermal conductivity through the aluminium profiles towards the aluminium panels forming the interior of the trolley.
Due to the above, the system of refrigeration known in the state of the art and cold maintenance for the foods and beverages contained in the trolleys is not very efficient, causing financial losses for the airlines since the foods contained in these trolleys must occasionally be discarded to prevent possible passenger intoxications, since microorganisms can proliferate.
The present invention solves the problem of lack of homogeneity in the refrigeration of the food and beverage storage elements located inside the trolley by establishing means which give rise to a different cold distribution, resulting in a homogeneous cold supply in addition to being able to store therein a larger amount of cold sources and having much lower losses of such cold, especially if the system is combined with a trolley for aircraft with a body constructed in expanded foamed material, all of which leads to a better distribution, increase of the cold source storage capacity and longer refrigeration maintenance time.
Additionally, the proposed technical solution increases the structural rigidity of the trolley and reduces the number of mobile (removable) parts thereof, which would lead to the elimination of breakdowns of the current type of container tray, in which the spring closures manufactured in plastic incorporated therein break, being able to cause the cold source to fall to the floor and injuries to people, or they do not enter their housing and/or closures are not engaged in the housings arranged for that purpose in the trolley when the trolley experiences an impact and is slightly deformed.